BOZEMAN, Mont. (AP) — A southern Montana woman who caused a crash that killed a 31-year-old man has been sentenced to 10 years in prison.

The Bozeman Daily Chronicle reports 29-year-old Natasha Lopez was sentenced Monday for the May 21, 2017, death of Stefan St. Armand. She was previously convicted of felony negligent homicide but acquitted of the more serious charge of vehicular homicide while under the influence.

Prosecutors say she was driving drunk when her car drifted off the side of the road and rolled in Bozeman, but defense attorneys argued that St. Armand was driving.

They called the investigation into the crash "flimsy" and noted that St. Armand had alcohol, methamphetamine and amphetamine in his system at the time.

Lopez's prison term will be followed by 10 years of probation.